Heating surface optical fiber stress monitoring device

Abstract

The utility model belongs to the field of stress monitoring equipment, and discloses a heating surface optical fiber stress monitoring device, which comprises a packaging main body, Fabry optical fiber sensors and optical fibers, the packaging main body is provided with four branches, the packaging main body and the branches form an X-shaped structure, the Fabry optical fiber sensors are arranged in the branches, and the Fabry optical fiber sensors are arranged in the packaging main body. Opposite Fabry optical fiber sensors are installed on the same axis, the Fabry optical fiber sensors on the same axis are connected through optical fibers, and the whole stress monitoring device is sealed through sealant. The utility model provides a novel packaging structure of an optical fiber stress monitoring device, so that stress in different directions can be monitored, the defect that an existing sensor can only monitor stress in one direction on a heating surface of a boiler is overcome, the sensor is packaged in a closed manner, and erosive wear of smoke dust in the boiler is effectively reduced.

Description

Technical Field

[0001] The utility model belongs to the field of stress monitoring equipment, and in particular relates to a heated surface optical fiber stress monitoring device. Background Art

[0002] The heating surface is an important component of the boiler. It consists of many pipes and plays an important role in the operation of the boiler. However, on the one hand, the frequent changes in the unit load will cause thermal stress and vibration, which will eventually cause alternating forces and thermal fatigue, and then thermal overheating will lead to reduced strength. On the other hand, the capacity of thermal power units is getting larger and larger, the coal quality is getting worse, the boiler steam parameters are constantly increasing, and the layout of the heating surface of the superheater and reheater is also increasing. The working medium flowing in the boiler superheater and reheater tubes is high-parameter steam and is located in a high-temperature area, with a harsh working environment. Due to various reasons, the actual temperature of the tube wall will exceed the design value during movement. When a short-term, small overheating occurs, the metal creep rate is slow, and its destructiveness will not appear immediately. However, when the tube is operated under overheating conditions for a long time, the metallographic structure of the tube will slowly change, the creep rate will gradually increase, and the material strength will continue to decrease, resulting in a shortened service life of the tube. In severe cases, overheating and tube bursting accidents will occur, endangering the safety of the unit.

[0003] Therefore, it is very important to monitor the stress of the boiler heating surface, which can control the stress distribution of the boiler heating surface in real time. However, general sensors can only monitor stress changes in a linear direction and cannot achieve all-round monitoring of the stress of the boiler heating surface. Utility Model Content

[0004] The utility model aims to provide a heating surface optical fiber stress monitoring device to solve the above technical problems.

[0005] In order to achieve the above-mentioned purpose, the specific technical scheme of a heating surface optical fiber stress monitoring device of the utility model is as follows:

[0006] A heated surface optical fiber stress monitoring device comprises a packaging body, a Fabry optical fiber sensor and an optical fiber. The packaging body has four branches. The packaging body and the branches are in an "X"-shaped structure. Fabry optical fiber sensors are installed in the branches. Opposite Fabry optical fiber sensors are installed on the same axis. The Fabry optical fiber sensors on the same axis are connected by optical fibers. The device as a whole is sealed with sealant.

[0007] Furthermore, the branch has a cylindrical groove, and the groove is used to fix the Fabry fiber sensor.

[0008] Furthermore, the optical fiber stress monitoring device is installed on the surface of the boiler heating surface, and the packaging body is tightly connected to the branch and the boiler heating surface.

[0009] Furthermore, the material of the packaging body and the branches is consistent with the heating surface of the boiler.

[0010] Furthermore, two Fabry fiber sensors in the same direction are connected in series.

[0011] Furthermore, the packaging body and the branches are hollow structures, and the Fabry fiber optic sensor and the optical fiber are filled with high-temperature sealant for sealing after installation.

[0012] Furthermore, the two groups of optical fibers are staggered in an "X" shape.

[0013] Furthermore, the plurality of stress monitoring devices are distributed in a network shape.

[0014] Furthermore, each branch has a through hole, and the optical fiber passes through the through hole.

[0015] Furthermore, the optical fiber is connected to other identical optical fiber stress monitoring devices to form a mesh structure to monitor the stress of the boiler heating surface.

[0016] The utility model provides a heating surface optical fiber stress monitoring device with the following advantages:

[0017] The utility model proposes a new packaging structure of an optical fiber stress monitoring device, which enables stresses in different directions to be monitored, overcoming the defect that the existing sensor can only monitor stress in one direction on the heating surface of the boiler. The device performs closed packaging on the sensor, effectively reducing the scouring and wear of smoke in the boiler. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1a It is a schematic diagram of the structure of the utility model;

[0019] Figure 1b It is a cross-sectional view of the structure schematic diagram of the utility model;

[0020] Figure 2 It is an isometric schematic diagram of the utility model.

[0021] Explanation of the markings in the figure: 1. Package body; 11. Branch; 12. Through hole; 2. Fabry fiber sensor; 3. Optical fiber. DETAILED DESCRIPTION

[0022] In order to better understand the purpose, structure and function of the utility model, the utility model is further described in detail below with reference to the accompanying drawings.

[0023] The utility model discloses a heated surface optical fiber stress monitoring device, which comprises a packaging body 1, a Fabry optical fiber sensor 2 and an optical fiber 3.

[0024] Depend on Figure 1aIt can be seen that the package body 1 has four branches 11, and the package body 1 and the branches 11 are in an "X"-shaped structure. A Fabry fiber sensor 2 is installed in the branch 11. The branch 11 has a cylindrical groove to fix the Fabry fiber sensor 2. The opposite Fabry fiber sensors 2 are installed on the same axis. The Fabry fiber sensors 2 on the same axis are connected through the optical fiber 3. After the whole is packaged, it is sealed with a high-temperature sealant. The optical fiber stress monitoring device is installed on the surface of the boiler heating surface. The package body 1 and the branches 11 need to be tightly connected to the boiler heating surface and properly fixed. They fit the boiler heating surface without displacement. The material selection of the package body 1 and the branches 11 is consistent with or similar to the boiler heating surface, which can reduce the strain difference caused by different materials. When stress is generated on the boiler heating surface in a certain direction, the "X"-shaped branch will capture the stress from that direction and generate corresponding deformation. The Fabry fiber sensor 2 that runs through the branch is fixed at both ends, and the deformation generated by the branch is transmitted to the optical fiber 3 extending from the Fabry fiber sensor 2. The Fabry fiber sensor 2 will therefore output a corresponding signal. By analyzing the signals transmitted by the four Fabry fiber sensors 2 on the branch, the direction in which the stress is generated can be determined, thereby monitoring the stress on the boiler heating surface.

[0025] Depend on Figure 1b It can be seen that there is a cylindrical groove in the branch 11, which can fix the Fabry fiber sensor 2. The Fabry fiber sensors 2 in the same direction should be installed on the same axis to avoid the optical fiber 3 twisting and generating strain, which affects stress monitoring. There are two Fabry fiber sensors 2 in series in the same direction.

[0026] The packaging body 1 and the branch 11 are hollow structures. After the Fabry fiber optic sensor 2 and the optical fiber 3 are installed, they can be filled with high-temperature sealant and sealed. The Fabry fiber optic sensor 2 is embedded in each branch 11 and will not be displaced. The Fabry fiber optic sensors 2 on the same axis are connected by the optical fiber 3. The two groups of optical fibers are staggered in an "X" shape to ensure that there is a certain tension at both ends of the optical fiber.

[0027] Specifically, the branch 11 in this structure can receive stress transmitted from any direction of the boiler heating surface. The deformation of the branch 11 will be transmitted to the Fabry fiber optic sensor 2 installed in the branch 11 for measurement. Stress in different directions will be received simultaneously by the four branches 11. The branch angle is fixed relative to the packaging body 1. The stress is decomposed into horizontal and vertical forces according to the trigonometric function. The deformation size generated by the same stress received by each branch 11 is inconsistent. All stresses in the horizontal and vertical directions are superimposed and converted into angle values ​​relative to the packaging body 1 to determine the angle of the stress relative to the device.

[0028]

[0029] In the formula, x1, x2, x3, and x4 are the horizontal forces of the stress decomposition on the four branches 11, y1, y2, y3, and y4 are the vertical forces of the stress decomposition on the four branches 11, x is the sum of the horizontal forces, y is the sum of the vertical forces, and α is the angle value relative to the center of the packaging body 1.

[0030] A plurality of stress monitoring devices are distributed in a network. According to four or more adjacent stress monitoring devices, the intersection of the direction extension lines determined by the branches of each stress monitoring device can locate the orientation of a certain stress point, thereby locating the stress direction.

[0031] Figure 2 It is an isometric schematic diagram of the utility model, and the details are as follows.

[0032] As can be seen from the figure, each branch 11 has a through hole 12 through which the optical fiber 3 can pass.

[0033] The optical fiber 3 can be connected to other similar stress monitoring devices to form a network structure to monitor the stress of the boiler heating surface.

[0034] It is understood that the present invention is described by some embodiments, and those skilled in the art are aware that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the scope of protection of the present invention.

Claims

1. A heated surface optical fiber stress monitoring device, comprising a packaging body (1), a Fabry optical fiber sensor (2) and an optical fiber (3), characterized in that: The package body (1) has four branches (11), the package body (1) and the branches (11) are in an "X"-shaped structure, Fabry optical fiber sensors (2) are installed in the branches (11), the opposite Fabry optical fiber sensors (2) are installed on the same axis, the Fabry optical fiber sensors (2) on the same axis are connected by optical fibers (3), and the entire device is sealed with a sealant.

2. The heated surface optical fiber stress monitoring device according to claim 1, characterized in that: The branch (11) has a cylindrical groove therein, and the groove is used to fix the Fabry optical fiber sensor (2).

3. The heated surface optical fiber stress monitoring device according to claim 1, characterized in that: The optical fiber stress monitoring device is installed on the surface of the boiler heating surface, and the packaging body (1) is tightly connected to the branch (11) and the boiler heating surface.

4. The heated surface optical fiber stress monitoring device according to claim 1, characterized in that: The material of the packaging body (1) and the branch (11) is consistent with the heating surface of the boiler.

5. The heated surface optical fiber stress monitoring device according to claim 1, characterized in that: Two Fabry fiber sensors (2) in the same direction are connected in series.

6. The heated surface optical fiber stress monitoring device according to claim 1, characterized in that: The packaging body (1) and the branch (11) are hollow structures, and the Fabry optical fiber sensor (2) and the optical fiber (3) are filled with high-temperature sealant for sealing after installation.

7. The heated surface optical fiber stress monitoring device according to claim 1, characterized in that: The two groups of optical fibers (3) are interlaced in an "X" shape.

8. The heated surface optical fiber stress monitoring device according to claim 1, characterized in that: Multiple stress monitoring devices are distributed in a network.

9. The heated surface optical fiber stress monitoring device according to claim 1, characterized in that: Each branch (11) has a through hole (12), and the optical fiber (3) passes through the through hole (12).

10. The heated surface optical fiber stress monitoring device according to claim 8, characterized in that: The optical fiber (3) is connected to other identical optical fiber stress monitoring devices to form a mesh structure for monitoring the stress of the boiler heating surface.

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